Implantable medical devices may be configured to deliver electrical stimulation therapy and/or monitor physiological signals. Electrical stimulation of neural tissue, for example, may provide relief for a variety of disorders, improving the quality of life for many patients. Some implantable medical devices may employ elongated electrical leads that carry electrodes. For example, electrodes may be located at a distal portion of a lead. A proximal portion of the lead may include electrical contacts that are coupled to the electrodes and coupled to terminal in an implantable medical device housing, which may contain electronic circuitry such as electrical stimulation generation circuitry and/or sensing circuitry. In some examples, stimulation may be conducted using multiple electrodes and multiple stimulation leads in order to provide electrical stimulation at multiple positions within the patient or to provide electrical stimulation to a targeted area.